ERBB2 and breast cancer: In the WSG-PRIMe study, which stands for West German Study Group-PRospective Study to Measure the Impact of MammaPrint on Adjuvant Treatment in Hormone Receptor-positive HER2-negative Breast Cancer Patients, 452 HR +ve/Her2 -ve with up to three involved LNs were recruited, and 63.5% of patients were assigned to the low-risk category (84).